From when they first opened in 1838 to when they finally closed in 1961, the mines at Greenside yielded 400,000 tons of lead and 7.5 million ounces of silver all gotten from 1.3 million tons of milled rock. Some zinc, a by product of lead smelting, was also produced. A tiny amount of gold was additionally found, but was unprofitable to extricate. This was the most productive and lucrative mine in the whole of the Lake District.

The lead was obtained from a great profusion of unusual and variously coloured lead ores, many uniquely found only in the Lake District. Galena, lead sulphide, was the most commonly found ore of lead. At the time the ore was mined, a great deal of then useless gangue material in the form of barytes (barium sulphate) had to be extracted and dumped elsewhere. This once considered useless material is now highly valued as a heavy sludge for displacing crude oil in reluctant oil fields.

The mine itself had a great many shafts, tunnels and adits at a multitude of different depths, some as much as 3000 feet below ground. Tunnels and levels spread out in a vast underground network stretching to Helvellyn, Sheffield Pike and Glencoynedale. Four dams, the remains of which can still be seen at Red Tarn, Kepple Cove and on Sticks Gill, supplied water to power the machinery and for washing the ore. There was also a waterwheel in the stream just below the Bury Hostel. An extensive network of leats on either side of the valley) scavenged water from the streams on the surrounding fells and entrained it into either the dammed tarns or into the river upstream of the waterwheel. The streams have since been re-diverted from the leats back into their original courses. Traces of a much later pipeline serving a water-powered turbine provided electrical power for underground lighting can be discerned hurtling down the steep slopes from Birkhouse Moor.

In 1927 the dam at Kepple Cove was suddenly breached by a heavy rainfall from a tempestuous cloudburst resulting in a tidal wave of water rushing down the valley, washing away everything in its path. The torrent raged down through the miners cottages to Glenridding leaving great devastation and havoc in its wake. A second and bigger dam further downstream was built to replace it. All four dams have now been broken to prevent any similar accidents recurring.

In 1959 and the mines final years it was used by the AWRE (Atomic Weapons Research Establishment) for an experiment in the propagation of seismic shock waves. A large, but conventional (non-nuclear), explosion was carried out in the middle of one of the deepest man-made caverns, to find out if atomic weapons testing could be hidden from remote detection by de-coupling it from the surrounding rocks by a cushion of air. The answer was 'no'. The explosion has rendered much of the mines tunnels and shafts highly unstable and entry has been barred for many years.

The stone huts and buildings at Greenside, including the Bury Hostel, were all once part of the mining complex. Many others have been demolished.
A view up Swart Beck to Sticks Pass